Quantcast
  • Register
PhysicsOverflow is a next-generation academic platform for physicists and astronomers, including a community peer review system and a postgraduate-level discussion forum analogous to MathOverflow.

Welcome to PhysicsOverflow! PhysicsOverflow is an open platform for community peer review and graduate-level Physics discussion.

Please help promote PhysicsOverflow ads elsewhere if you like it.

News

PO is now at the Physics Department of Bielefeld University!

New printer friendly PO pages!

Migration to Bielefeld University was successful!

Please vote for this year's PhysicsOverflow ads!

Please do help out in categorising submissions. Submit a paper to PhysicsOverflow!

... see more

Tools for paper authors

Submit paper
Claim Paper Authorship

Tools for SE users

Search User
Reclaim SE Account
Request Account Merger
Nativise imported posts
Claim post (deleted users)
Import SE post

Users whose questions have been imported from Physics Stack Exchange, Theoretical Physics Stack Exchange, or any other Stack Exchange site are kindly requested to reclaim their account and not to register as a new user.

Public \(\beta\) tools

Report a bug with a feature
Request a new functionality
404 page design
Send feedback

Attributions

(propose a free ad)

Site Statistics

205 submissions , 163 unreviewed
5,082 questions , 2,232 unanswered
5,353 answers , 22,789 comments
1,470 users with positive rep
820 active unimported users
More ...

  Where is the mass of a Schwarzschild black hole located?

+ 0 like - 0 dislike
848 views

The entropy of a Schwarzschild black hole is located near the horizon, and the moment of inertia of a Schwarzschild black hole is $MR^2$. Both aspects imply that the mass of a Schwarzschild black hole is distributed across the horizon and near the horizon. But a Nobel prize was just given, in 2020, for a black hole singularity theorem.

Is the black hole mass located near the center, or it is located near the horizon?

asked Nov 7, 2020 in Astronomy by Christian [ no revision ]
recategorized Nov 8, 2020 by Dilaton

1 Answer

+ 1 like - 0 dislike

A particle dropping into a Schwarzschild black hole takes an infinite time to reach the horizon if observed from the outside. Thus, if a Schwarzschild black hole forming in a collapse is observed, this would suggest that, at any finite time, some mass at least is located outside the horizon, near to it.

On the other hand, if you look at the pure Schwarzschild solution, this is based on an energy-momentum tensor which vanishes everywhere, in particular at the horizon. 

The singularity theorems show that solutions to the Einstein field equations may have singularities under generic conditions. The relevance of this is that singularities are not artifacts which appear only under very special symmetry conditions (which conditions might be considered without physical relevance in real astrophysical situations).

answered Nov 7, 2020 by Flamma (110 points) [ no revision ]

Your answer

Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead.
To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL.
Please consult the FAQ for as to how to format your post.
This is the answer box; if you want to write a comment instead, please use the 'add comment' button.
Live preview (may slow down editor)   Preview
Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:
p$\hbar$ysic$\varnothing$Overflow
Then drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds).
Please complete the anti-spam verification




user contributions licensed under cc by-sa 3.0 with attribution required

Your rights
...